Hi all,
I used Gmsh to create a very simple mesh, a cube, which has 3 boundary types, then I converted it using gmshToFoam and I got this warning:

--> FOAM Warning :
From function polyMesh::polyMesh(... construct from shapes...)
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 577
Found 1222 undefined faces in mesh; adding to default patch.

When I loaded the mesh in ParaView it was ok. Then I loaded it through FoamX and i saw in my geometry 4 patches, the 3 I defined and defaultFaces. Where is my error? please can anyone give me a hint? Can you explain me what is the meaning of these faces? Are them the internal element faces?

If you need I can send you my file, I don't know how to upload it (maybe someone could explain me how to do it?).

The defaultFaces are all the boundary faces that have not otherwise been assigned to a particular patch. Assuming that they correspond to some walls that you did not explicity define, you'll likely wish to change them from 'empty' to 'wall' in constant/polyMesh/boundary